Datasheet

MAX1776
24V, 600mA Internal Switch, 100% Duty Cycle,
Step-Down Converter
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, V
IN
= +12V, SHDN = IN, T
A
= 0°C to +85°C, unless otherwise noted.)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
IN, SHDN, ILIM, ILIM2 to GND .................................-0.3V to 25V
LX to GND.......................................................-2V to (V
IN
+ 0.3V)
OUT, FB to GND .........................................................-0.3V to 6V
Peak Input Current .................................................................. 2A
Maximum DC Input Current.............................................. 500mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin µMAX (derate 4.1mW/°C above +70°C) .............330mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Input Voltage Range V
IN
4.5 24 V
Input Supply Current I
IN
No load 15 28 µA
Input Supply Current in Dropout I
IN
(
DROP
)
No load 50 70 µA
Input Shutdown Current SHDN = GND 3 7 µA
V
IN
rising 3.6 4.0 4.4
Input Undervoltage Lockout
Threshold
V
UVLO
V
IN
falling 3.5 3.9 4.3
V
Output Voltage (Preset Mode) V
OUT
FB = GND 4.80 5.00 5.20 V
Feedback Set Voltage
(Adjustable Mode)
V
FB
1.212 1.25 1.288 V
OUT Bias Current V
OUT
= 5.5V 1.65 3.5 6.25 µA
OUT Pin Maximum Voltage 5.5 V
FB Bias Current I
FB
V
FB
= 1.3V -25 +25 nA
FB Dual Mode™ Threshold Low 50 100 150 mV
LX Switch Minimum Off-Time t
OFF
(
MIN
)
0.22 0.42 0.62 µs
LX Switch Maximum On-Time t
ON
(
MAX
)
V
FB
= 1.3V 8 10 12 µs
ILIM = ILIM2 = GND 1.6 3.2
ILIM = GND, ILIM2 = IN 0.8 1.6
ILIM = IN, ILIM2 = GND 0.4 0.8
V
IN
= 6V
ILIM = ILIM2 = IN 0.4 0.8
ILIM = ILIM2 = GND 1.9 3.8
ILIM = GND, ILIM2 = IN 1.0 1.9
ILIM = IN, ILIM2 = GND 0.5 0.95
LX Switch On-Resistance R
LX
V
IN
= 4.5V
ILIM = ILIM2 = IN 0.5 0.95
Ω
ILIM = ILIM2 = GND 120 150 180
ILIM = GND, ILIM2 = IN 240 300 360
ILIM = IN, ILIM2 = GND 480 600 720
LX Current Limit I
LX
(
PEAK
)
ILIM = ILIM2 = IN 960 1200 1440
mA
LX Zero-Crossing Threshold -75 +75 mV
Zero-Crossing Timeout LX does not rise above the threshold 30 µs
T
A
= +25°C1
LX Switch Leakage Current
V
IN
= 24V,
LX = GND
T
A
= 0°C to +85°C10
µA
Dual Mode is a trademark of Maxim Integrated Products, Inc.